{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T20:36:59Z","timestamp":1773693419684,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,26]],"date-time":"2022-05-26T00:00:00Z","timestamp":1653523200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of Science, Innovation and Universities and EFRD, \u201cSensing with Pioneering Opportunistic Techniques\u201d SPOT","award":["RTI2018-099008-BC21\/AEI\/10.13039\/501100011033"],"award-info":[{"award-number":["RTI2018-099008-BC21\/AEI\/10.13039\/501100011033"]}]},{"name":"Spanish Ministry of Science, Innovation and Universities and EFRD, \u201cSensing with Pioneering Opportunistic Techniques\u201d SPOT","award":["RYC-2016-20918"],"award-info":[{"award-number":["RYC-2016-20918"]}]},{"name":"Unidad de Excelencia Maria de Maeztu MDM-2016-0600","award":["RTI2018-099008-BC21\/AEI\/10.13039\/501100011033"],"award-info":[{"award-number":["RTI2018-099008-BC21\/AEI\/10.13039\/501100011033"]}]},{"name":"Unidad de Excelencia Maria de Maeztu MDM-2016-0600","award":["RYC-2016-20918"],"award-info":[{"award-number":["RYC-2016-20918"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Ionospheric perturbations affect the propagation of electromagnetic waves. These perturbations, besides being a problem for space communications, satellite navigation, and Earth observation techniques, could also be used as another Earth observation tool. Several recent studies showed correlations with earthquakes with ionospheric anomalies, but almost all of them use ground stations to measure the Total Electron Content (TEC) variations, and, in particular, the ones occurring after an earthquake. Here, a preliminary study is presented on how the ionospheric scintillation measured with GNSS-R instruments over oceanic regions shows a small, but detectable correlation with the occurrence of earthquakes, which in some cases occurs before the earthquakes. This study uses GNSS-R data from NASA CYGNSS Mission to measure the ionospheric amplitude scintillation (S4) for 6 months from March 2019 to August 2019, applying a statistical analysis based on confusion matrixes, and the Receiver Operating Characteristic (ROC) curves to correlate S4 anomalous variations to earthquakes. A small positive correlation is found between the ionospheric scintillation and the earthquakes during the six previous days. However, the study has some weakness because (a) a small number (\u223c45) of large (M &gt; 6) earthquakes over oceanic regions are studied, (b) the region studied is close to the geomagnetic equator, where ionospheric scintillations are usual, and (c) the overall correlation is small.<\/jats:p>","DOI":"10.3390\/rs14112555","type":"journal-article","created":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T00:25:12Z","timestamp":1653956712000},"page":"2555","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["A Preliminary Study on Ionospheric Scintillation Anomalies Detected Using GNSS-R Data from NASA CYGNSS Mission as Possible Earthquake Precursors"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0300-4106","authenticated-orcid":false,"given":"Carlos","family":"Molina","sequence":"first","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, 08034 Barcelona, Spain"},{"name":"IEEC-Institut d\u2019Estudis Espacials de Catalunya, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0671-4808","authenticated-orcid":false,"given":"Badr-Eddine","family":"Boudriki Semlali","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0031-0802","authenticated-orcid":false,"given":"Hyuk","family":"Park","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, 08034 Barcelona, Spain"},{"name":"IEEC-Institut d\u2019Estudis Espacials de Catalunya, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9514-4992","authenticated-orcid":false,"given":"Adriano","family":"Camps","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, 08034 Barcelona, Spain"},{"name":"IEEC-Institut d\u2019Estudis Espacials de Catalunya, 08034 Barcelona, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1007\/s10712-015-9319-1","article-title":"A review of ionospheric scintillation models","volume":"36","author":"Priyadarshi","year":"2015","journal-title":"Surv. 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